Bosch Dryer Error E17 — What It Means & How to Fix It

What Does This Error Mean?

E17 on a Bosch dryer indicates a secondary airflow restriction or exhaust monitoring fault. The dryer's sensors have detected that air is not moving through the system at the expected rate. This is closely related to E06 (exhaust blocked) but is triggered by a different sensor or at a different point in the airflow path.

Affected Models

Bosch WTW87565GB
Bosch WTH84000GB
Bosch Serie 6 and Serie 8 Heat Pump and Condenser Dryers
Bosch WQB145B0GB

Common Causes

Lint filter partially blocked — restricting air movement through the drum
Secondary internal air channel clogged with lint that bypassed the filter
Exhaust hose (vented models) kinked or partially obstructed
Airflow sensor or pressure switch fault — incorrectly reading airflow
Fluff filter in the heat exchanger area (heat pump models) blocked

How to Fix It

Clean the lint filter and the filter housing slot thoroughly.

Remove all lint from the filter mesh and the slot it sits in. Use a soft brush or vacuum to reach inside the slot.
For heat pump models — clean the heat exchanger fluff filter.

Bosch heat pump dryers have a second filter protecting the heat exchanger. Open the lower front panel to access it. Rinse it under a tap and allow it to dry fully before reinstalling.
For vented models — inspect the full length of the exhaust hose.

A hose that has shifted position, developed a kink, or partially blocked with compacted lint restricts airflow enough to trigger E17.
Leave the dryer door open for 30 minutes to air out, then restart.

If E17 was caused by a marginal blockage that the cleaning has resolved, the dryer should restart normally.
If E17 persists, book a Bosch service visit — internal lint in the air channel needs professional cleaning.

Annual professional servicing prevents internal lint buildup and extends dryer life significantly.

When to Call a Professional

If cleaning the lint filter and heat exchanger does not resolve E17, a technician is needed. Internal lint blockages in the air channel require the dryer to be partially disassembled. A technician can also test the airflow sensor to confirm if it has failed.

Frequently Asked Questions

How often should I clean the Bosch dryer heat exchanger filter?

Bosch recommends cleaning the heat exchanger filter every 5 cycles on heat pump models. In practice, most owners clean it monthly — more often if drying heavy items like towels or bedding. A blocked heat exchanger filter is the most common cause of E17 on heat pump dryers.